1. Field of the Invention
The present invention relates to a sound absorbing material to be attached on a fence, a side wall, a ceiling, or the like which surrounds a noise source.
2. Prior Art
Conventionally, a number of structures have been employed as a fence, a side wal, or the like, surrounding a noise source. Japanese Patent Publication No. 51-46969/1976 (FIGS. 1(A)-1(G) discloses a structure in which cylindrical bodies of glass wool are fixed on the upper edge of a sound-insulation fence. Japanese 59-41400/1984 discloses a structure in which a sound absorbing board is stuck on the side of a sound-insulation fence (see FIGS. 2A, 2B).
In the sound absorbing structures as disclosed in the above-mentioned publications, it is possible to provide some degree of sound absorbing or soundproofing effects. However, problems arise in these structures in that positional limitations exist in the applications of the structures, directivity exists in the sound absorbing characteristics and the work necessary to attach the structures is troublesome and so on.
It is therefore an object of the present invention to provide a sound absorbing material which requires no directivity in sound absorbing characteristics, and hence, has no positional limitations in applications of the sound absorbing material.
It is a further object of the present invention to provide a sound absorbing material which is strong.
it is a further object of the present invention to provide a sound absorbing material which is easy to attach.
It is a further object of the present invention to provide a sound absorbing material which yields a high degree of sound absorbing performance.